Heavy soles have been provided on golf clubs to lower their center of gravity and thereby improve the balance of the clubs during the stroke. As an example of such a club, U.S. Pat. No. 5,527,034 to Ashcraft et al. discloses a golf club head having an aluminum or brass body and a separate sole that fits into cavity which must be machined into the body. The sole is weighted, that is, the sole is made of even a heavier material than is the body of the club head, thereby lowering the center of gravity of the head.
As recognized by the present invention, not only do weighted club heads exhibit improved balance, but they can also result in a golfer imparting a greater impact on the ball during the stroke than the golfer would otherwise impart with an unweighted club head. This enables the golfer to hit the ball farther than he or she otherwise would, thus improving the golfer's game.
As further recognized herein, however, a golf club head can deform slightly when impacting a golf ball, thereby reducing the energy imparted to the ball by the club, regardless of whether the head is weighted. In other words, the effect of a weighted head in enabling a golfer to hit a ball farther than he or she otherwise would unfortunately is mitigated somewhat by head deformation during the stroke. Fortunately, the present invention recognizes that it is possible to reduce the deformation of a golf club head as it strikes a golf ball.
In addition to the above consideration, weighted soles, such as the one disclosed in the above-mentioned patent, are precisely fitted into a cavity in the bottom of the head. This has two drawbacks. First, precise machining of the weighted sole is required to fit it into the cavity, which entails rather small manufacturing tolerances and concomitant higher manufacturing costs. Second, the thickness of the sole cannot be ascertained once it is disposed in the cavity. As recognized herein, it is desirable to reduce manufacturing tolerances (and, thus, costs), as well as to enable a golfer to easily ascertain the thickness of a weighted sole.